Pulley-block



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S. F. LEWIS, OF SAN FRANCISCO, CALIFORNIA.

PULLEY-BLOCK.

Specification of Letters Patent No.

To all whom 'it 'may concern:

Be it known that I, S. F. LEwrs, of San Francisco, in the county of San Francisco and State of California, have invented a new and Improved Stop-Block; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making a part of this specification, in which- Figure l, is a perspective view of my invention applied to its work, Fig. 2, is a vertical section of ditto taken in the line m, Fig. 3, Fig. 3, is a vertical section of ditto taken in the line y, y, Fig. 2.

Similar letters of reference indicate cor-` responding' parts in the several figures.

This invention consists in the employment or use of an eccentric and shoe placed within the block and arranged relatively with the pulley as hereinafter shown and described, whereby said parts, when used in connection with stops on the pulley and a stop on the shoe, enable the attendant to control the movement of the rope, checking or stopping it entirely when the article to be elevated is at the proper height and the power is to be detached and regulating the descent of the article as may be required.

The invention is applicable to all purposes where stop blocks are used but is more especially designed for discharging cargoes from vessels and similar purposes where a horse or animal is employed for elevating the articles.

To enable those skilled in the art to fully understand and construct my invention I will proceed to describe it.

A, represents a block which may be constructed of wood and in the usual way the cheek pieces being' protected by a metal strap B. Within the block A, a pulley C is placed. This pulley may be of metal, at least such material would be preferable, the pulley being placed on a suitable pin or aXis a. The periphery of the pulley C, is grooved as shown clearly in Fig. 3, and on one side of the pulley teeth or projections b, are formed as shown clearly in Figs. 2 and 3.

Within the block A, and below the pulley 26,038, dated November 8, 1859.

C, a shoe D, is placed. This shoe is also of metal and its upper edge is of concave form, corresponding inversely or concentric with the periphery of the pulley C, see Fig. 2. The shoe D, is provided with a stop c, which correspond in form with the teeth or projections Z), on the pulley C. The lower edge of the shoe D, is concave and an eccentric E, lits therein and between the shoe and a strap d, attached thereto. The aXis c, of the eccentric passes through the block A, and a lever F, is attached to one end of it. The upper concave edge of the pulley is grooved similarly to the periphery of the pulley.

G, is the rope which passes around the pulley C, between it and the shoe D.

In Fig. l, the block is shown applied to its work, the lower end of the block being provided with a screw f, which serves to secure it in proper position at the desired place. The rope G, has a horse or animal attached to one end of it and the other end passes through a shieve attached to a swinging boom. The article to be raised being attached to t-he opposite end of the rope.' The article it will be seen is raised by the movement of the horse and when elevated to the desired height the attendant actuates the lever F, and thereby turns the eccentric E, which throws the shoe D, toward the pulley C, and the stop c, of the shoe will project over the side of the pulley C, and serve as a stop to the teeth b thereby arresting the motion of the pulley C, at the same time the rope Cr, is prevented from moving on account of the pressure to which it is subjected between the pulley C, and shoe D. The stop 0, therefore of the shoe D, and the teeth or projections of the pulley C, form an arbitrary stop movement and elfectually prevent the rotation of the pulley. When the pulley C, is stopped by this movement of the shoe D, the horse or other power may be detached from rope Gr, and the shoe D, allowed to descend by a proper movement of the lever F, and consequent turning of eccentric E, and the article is allowed to descend with a greater or less speed according to the amount of pressure exerted on the rope between the pulley C, and shoe D.

Having thus described my invention What formed respectively on the pulley C, and I claim as new and desire to secure by Letshoe D7 to operate as and for the purpose 10 ters Patent, is set forth.

l. The arrangement and combination of 5 the pulley C, shoe D, and eccentric E, With- S F' LEWIS' fr in the block A., as and for the purpose speci- Witnesses: l lied. E. FOSTER,

2. The teeth or projections b, and stop c, W. H. MOORE. v 

